1. Field of the Invention
The present disclosure relates to the field of production and purification of hydrofluoroolefin compounds. This invention particularly relates to a method for the co-manufacture of 1,2,3,3,3-pentafluoropropene (FC-1225ye) and 2,3,3,3-tetrafluoropropene (FC-1234yf) via the catalytic dehydrofluorination of 1,1,1,2,3,3-hexafluoropropane and 1,1,1,2,3-pentafluoropropane.
2. Description of Related Art
Chlorine-containing compounds such as chlorofluorocarbons (CFCs) are considered to be detrimental to the Earth's ozone layer. Many of the hydrofluorocarbons (HFCs), used to replace CFCs, have been found to contribute to global warming. Therefore, there is a need to identify new compounds that do not damage the environment, but also possess the properties necessary to function as refrigerants, solvents, cleaning agents, foam blowing agents, aerosol propellants, heat transfer media, dielectrics, fire extinguishing agents, sterilants and power cycle working fluids. Fluorinated olefins, especially those containing one or more hydrogens in the molecule (referred to herein as hydrofluoroolefins) are being considered for use in some of these applications such as in refrigeration as well as in processes to make fluoropolymers. Blends of HFC-1225ye and HFC-1234yf are useful as refrigerant compositions which have lower potential to contribute to global warming than refrigerant compositions such as blends of HFC-134a. Particularly useful are blends for HFC-1225ye and HFC-1234yf which contain greater than 50% by weight of HFC-1225ye, which renders the blend nonflammable
U.S. Pat. No. 6,369,284 describes a method for making HFC 1225ye or HFC 1225zc from HFC-236ea or HFC-236fa respectively by dehydrofluorination. U.S. Pat. No. 6,548,719 describes a method of dehydrohalogenating hydrofluorocarbons to produce hydrofluoroolefins such as HFC-1234ze using alkali metal hydroxides with phase transfer catalysts. U.S. Pat. Nos. 5,679,875 and 5,396,000 disclose a method for making HFC-1225ye from HFC-236ea via catalytic dehydrofluorination. Pending U.S. application Ser. No. 11/264,183 discloses dehydrofluorination of hydrofluorocarbons to produce hydrofluoroolefins.
Blends of HFC-1225ye and HFC-1234yf are particularly useful as refrigerant compositions which have lower global warming potential than hydrofluorocarbons currently in use. It would be useful from a manufacturing perspective to be able to directly manufacture a desired blend in a single process instead of having to blend the two HFC's produced individually.